01 Sierra Hard start when cold

[racindego]

First off, GM tech, I wish you the best of luck in your recovery.

 

I have a question for you or anyone else that may be able to help. I have an 01 Sierra 2500HD with a 6.0 litre. When the truck is cold, the cranking time seems to have gotten longer all of a sudden. Not obnoxiously so, like others have experienced, just noticeably longer. It also sometimes stumbles a little before it starts. When it is warm, it doesn't seem to do this. It fires right up.

 

Now, I have searched this forum and came to the conclusion that it was probably a fuel pump check valve or a fuel pressure regulator. The thing is, if I turn the ignition on and off a few times before starting it cold (to theoretically pressurize the injectors, if they did bleed down for some reason) the problem is just as noticeable. This doesn't seem to help at all.

 

I put a fuel pressure gauge on the truck and got around 55 psi with the key on. Pressure held after I turned the key off for well over 10 minutes without dropping at all. Also, there is no gas in my regulator vacuum line.

 

Help.

[ChevyTech007]

I would have your injectors cleaned (preferably with BG injector service). Also change your fuel filter. Even if you have good pressure the filter could limit volume.

[Razormann]

I would go after the Fuel Filter first, I was having some real odd cold start problems with my 94 Sierra on cold starts. After wasting a lot of time and a good amount of money a simple fuel filter solved the problem.

[racindego]

Thanks guys. I guess I can try a fuel filter. I did the seafoam treatment already.